Serial Host Interface (SHI) I2C Protocol Timing
Table 3-17 SHI I2C Protocol Timing (continued)
Standard I2C
Standard4, 5
Fast-Mode5, 6
Unit
Symbol/
Expression
No.
Characteristics1, 2, 3
Min
4.7
4.0
—
Max
—
Min
1.3
1.3
Max
175 SCL low period
176 SCL high period
TLOW
THIGH
—
—
µs
µs
—
177 SCL and SDA rise time
178 SCL and SDA fall time
179 Data set-up time
T
1000 20 + 0.1 × Cb 300
300 20 + 0.1 × Cb 300
ns
R
T
F
—
ns
TSU;DAT
THD;DAT
FDSP
250
0.0
—
—
100
0.0
—
ns
180 Data hold time
0.9
µs
181 DSP clock frequency
• Filters bypassed
MHz
10.6
11.8
13.1
—
—
—
28.5
39.7
61.0
—
—
—
• Narrow filters enabled
• Wide filters enabled
182 SCL low to data out valid
183 Stop condition setup time
TVD;DAT
TSU;STO
tSU;RQI
—
3.4
—
—
0.9
—
µs
µs
ns
4.0
0.0
0.6
0.0
184 HREQ in deassertion to last SCL edge (HREQ in set-up
time)
—
—
186 First SCL sampling edge to HREQ output deassertion2
• Filters bypassed
TNG;RQO
ns
ns
ns
ns
2 × TC + 30
2 × TC + 120
2 × TC + 208
—
—
—
50
—
—
—
50
• Narrow filters enabled
140
228
140
228
• Wide filters enabled
187 Last SCL edge to HREQ output not deasserted2
• Filters bypassed
TAS;RQO
2 × TC + 30
2 × TC + 80
2 × TC + 135
50
—
—
—
50
—
—
—
• Narrow filters enabled
100
155
100
155
• Wide filters enabled
188 HREQ in assertion to first SCL edge
• Filters bypassed
TAS;RQI
4327
4282
4238
—
—
—
927
882
838
—
—
—
0.5 × TI2CCP
0.5 × TC - 21
-
• Narrow filters enabled
• Wide filters enabled
187 First SCL edge to HREQ in not asserted (HREQ in hold
time.)
tHO;RQI
0.0
—
0.0
—
1
2
3
4
5
6
VCC = 1.8 V 5%; TJ = –40°C to +95°C, CL = 50 pF
Pull-up resistor: RP (min) = 1.5 kOhm
Capacitive load: Cb (max) = 400 pF
It is recommended to enable the wide filters when operating in the I2C Standard Mode.
The timing values are derived from frequencies not exceeding 100 MHz.
It is recommended to enable the narrow filters when operating in the I2C Fast Mode.
DSP56367 Technical Data, Rev. 2.1
Freescale Semiconductor
3-43